The present invention relates to a method and device or feeding an electronic component to an electronic component mounting device which picks up the electronic component with a suction nozzle and mounts it at a specific position on a circuit substrate.
In recent years, with the propagation of leadless electronic components (chip components), their configuration and size have been diversified, so that there has been much demand to obtain an even more accelerated operation and high reliability in an electronic component mounting device for mounting components onto a circuit substrate, so as to construct an electronic circuit by combining the variety of electronic components. It is thus necessary to enhance the efficiency in a component mounting operation under these circumstances, and it is thought to be effective to prevent decrease in the operation rate due to exhaustion of the components to be mounted. Specifically, it may be constructed such that the feeder section for supplying electronic components is divided in sections, on each of which is loaded electronic components of the same kind, and if one type of electronic components is exhausted during a component feeding operation, the electronic component of that type is fed from other feeder sections.
FIG. 6 is a perspective view showing the overall construction of a conventional electronic component mounting device based on the above idea. In the example shown here, the feeder section is divided into two parts for simplifying the explanation. In FIG. 6, both feeder sections 1, 2 are supported on an identical rail (not shown) such as to be movable along a direction Z shown in the figure. When the feeder section 1 or 2 loaded with electronic components is moved to a pick-up position, a suction nozzle unit 7 attached on the circumference of a rotary table 6 is lowered to pick up the electronic component. The suction nozzle unit 7, while holding the electronic component, goes upwards and moves along a circular path at a prescribed angle by means of the rotary table 6. Then, the suction nozzle unit 7 descends again for mounting the electronic component at a predetermined position on the circuit substrate 9 loaded on an X-Y table 8.
Here, the feeder section 1 or 2 moves as described below. As shown in FIG. 7(a), the feeder sections 1 and 2 respectively comprise a plurality of component supply units arranged in parallel. Now it is assumed that each of the component supply units of both feeder sections 1, 2 is loaded with all types of electronic components which need to be mounted, and at the moment components are being fed from a supply unit 3 of the feeder section 1. The other feeder section 2 is not in use, and such state will be hereinafter mentioned as being xe2x80x9con standbyxe2x80x9d. After a while, at least one type of electronic components in the feeder section 1 is used up, upon which the feeder section 2 starts feeding electronic components as shown in FIG. 7(b). The reference numeral 4 indicates a component supply unit which has run out of the electronic components. This state of feeder section 1 will be called a xe2x80x9ccomponent exhausted statexe2x80x9d. While electronic components are being fed from the feeder section 2, the component supply unit 4 which has run out of the components is replenished with the components and is made to be a supply unit 5 loaded with components as shown in FIG. 7(c), so that the feeder section 1 can be again in the standby state.
With the above described conventional construction, under the state shown in FIG. 7(c), the feeder section 2 needs to consume all of the components in order for the feeder section 1 to feed the electronic components again. Here, it is assumed that electronic components of one kind loaded on the feeder section 1 are left only in a small amount.
Referring to FIG. 8, at first the feeder section 1 feeds the electronic components while the other feeder section 2 is on standby. When the feeder section 1 runs out of one type of electronic components, the feeder section 2 starts component feeding. Meanwhile, the feeder section 1 is loaded with electronic components so as to be on standby. Here, electronic components which are replenished are only those which have been used up just before, and the components which still remain even in a small amount are normally not replenished. Successively, the feeder section 2 runs out of electronic components, and the feeder section 1 starts component feeding. Meanwhile, the feeder section 2 starts to be loaded with electronic components, however, the feeder section 1 soon runs out of the components, since some types of electronic components are left in a small amount, and if the loading of electronic components to the feeder section 2 has not yet been completed by this time, both of the feeder sections 1, 2 will soon run out of electronic components, causing the electronic component mounting device to come to a halt. This is one of the factors obstructing enhancement in the operation rate of the electronic component mounting device.
The present invention has been devised in view of the above described circumstance, its main purpose being to provide a method and device for feeding an electronic component with which shutdown of the device caused by shortage of components is prevented, whereby it is possible to enhance the operation rate.
To accomplish the above object, a first feature of the present invention is a method of feeding an electronic component wherein if one of a plurality of feeder sections, which are respectively loaded with electronic components of identical types, runs out of at least one type of electronic components during a component feeding operation, the other feeder section which has been in a standby state starts feeding the electronic components of the type which has been used up: In the method, when one of the feeder sections which are in a standby state is designated, the feeder section which is currently feeding electronic components is forcibly moved aside to a retracted position, and the designated feeder section is moved to a predetermined component feeding position.
With such construction, if one type of electronic components in the feeder section which is on standby is left only in a small amount, this feeder section is designated and moved to the component feeding position, by which components are supplied from this designated feeder section, and this feeder section is forcibly made to be in the component exhausted state, after which it is replenished with components and made to be in a standby state. It is thus possible to prevent a long-time pause of the electronic component mounting device due to shortage of components caused by exhaustion of components at several feeder sections at the same time, since the electronic components are kept from being left in a small amount on the feeder section. Accordingly, the operation rate of the electronic component mounting device can be enhanced.
A second feature of the present invention is a device for feeding an electronic component wherein if one of a plurality of feeder sections, which are respectively loaded with electronic components of identical types, runs out of at least one type of electronic components during a component feeding operation, the other feeder section which has been in a standby state starts feeding the electronic components of the type which has been used up. In this embodiment, the device includes first feeder section designating means for designating a desired one of the feeder sections which are in a standby state; and first feeder section controlling means for forcibly moving the feeder section which is currently feeding electronic components to a retracted position when another feeder section has been designated by the feeder section designating means, and for moving the designated feeder section which has been in a standby state to a predetermined component feeding position.
With the above construction, the same functions and effects as those of the first feature of the invention can be achieved.
A third feature of the present invention is a method of feeding an electronic component wherein if one of a plurality of feeder sections, which are respectively loaded with electronic components of identical types, runs out of at least one type of electronic components during a component feeding operation, the other feeder section which has been in a standby state starts feeding the electronic components of the type which has been used up. In the method, the number of remaining electronic components in each of the feeder sections which are in a standby state is counted, and if there are any feeder section of which counted number of component is fewer than a predetermined value, this feeder section is designated, whereupon the feeder section which is currently feeding electronic components is forcibly moved aside to a retracted position, and the designated feeder section is moved to a predetermined component feeding position.
With such construction, if one type of electronic components on the feeder section on standby is left only in a small amount, this feeder section is designated on the basis of comparison between the counted value of remainder number of components and a preliminarily determined value, and this designated feeder section is moved to the component feeding position, where components are fed from this feeder section, so that this feeder section is forcibly made to be in the component exhausted state, after which the feeder section is replenished with components so as to be in the standby state. It is thus possible to prevent a long-time pause of the electronic component mounting device due to shortage of components caused by exhaustion of components at several feeder sections at the same time, since the electronic components are kept from being left in a small amount on the feeder section. Accordingly, the operation rate of the electronic component mounting device can be enhanced.
A fourth feature of the present invention is a device for feeding an electronic component wherein if one of a plurality of feeder sections, which are respectively loaded with electronic components of identical types, runs out of at least one type of electronic components during a component feeding operation, the other feeder section which has been in a standby state starts feeding the electronic components of the type which has been used up. In this embodiment, the device includes second feeder section designating means for counting a number of remaining electronic components in each of the feeder sections which are in a standby state, and for designating any feeder section which has a fewer number of electronic components than a preliminarily determined value; and second feeder section controlling means for forcibly moving the feeder section which is currently feeding electronic components to a retracted position when another feeder section has been designated by the second feeder section designating means, and for moving the designated feeder section which has been in a standby state to a predetermined component feeding position.
With such construction, the same functions and effects as those of the above described third feature of the invention can be achieved.